Expression Of Mycobacterium Tuberculosis FurA And Preparation Of Its Monoclonal Antibodies

Mycobacterium tuberculosis (MTB) is an important human pathogen that causes serious infection worldwide. Overall, one-third of the world's population is currently infected with TB. TB remains an important global public health problem because there are 8 million new cases and 3 million deaths annually.One physiological condition known to be important in MTB infection is the availability of iron. As is the case for most organisms, MTB uses iron as a cofactor for enzymes that are involved in redox reactions and other essential functions, and it fails to grow in the absence of this metal. Free iron, however, is not readily available in the mammalian host, as it is mainly bound to high-affinity iron-binding proteins. On the other hand, abnormally high iron levels in MTB-infected humans are associated with exacerbation of the disease. In response to iron limitation, MTB, like many other bacteria,produces high-affinity iron chelators, i.e., siderophores, which in mycobacteria are defined as mycobactins. Supporting the concept that iron acquisition in the host is essential for virulence, failure to produce mycobactin results in defective bacillary multiplication in macrophages.In addition to possessing the ability to acquire iron in the host, successful pathogens and essentially all aerobic organisms must carefully control the level of intracellular iron. Failure to regulate this amount of iron in the cell could be lethal due to the ability of this metal to catalyze the production of toxic oxygen radicals in the presence of oxygen. Prokaryotes largely regulate intracellular iron levels by controlling its uptake. This is done by modifying the transcription of genes involved in iron acquisition, depending on the iron levels in the cell. Proteins that sense the levels of intracellular iron respond accordingly by modulating gene expression. MTB contains four potential iron-dependent regulators belonging to two different families of metalloregulatory proteins. Two genes, fur A and furB, encode the protein of Fur (ferric uptake regulator) family, while IdeR and SirR are members of the DtxR (diphtheria toxin repressor) family. Like DtxR and Fur, FurA binds iron and then interacts with a specific sequence in the operator regions of iron-regulated genes to control their transcription.The presence of fur A, immediately upstream of kotG in several mycobacterial species including MTB, may regulate a subset of oxidative stress response genes and increases both the resistance of this organism to H2O2 and its susceptibility to INH.In this study, furA gene segments were amplified by PCR with specific primers from genome of MTB H37Rv strain. After sequenced, furA gene...